Banca de DEFESA: MAXSUELL LUCAS MENDES MARQUES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MAXSUELL LUCAS MENDES MARQUES
DATE: 27/03/2026
TIME: 09:00
LOCAL: REMOTA
TITLE:

IN VITRO ANTIOXIDANT AND ANTI-ADIPOGENIC PROPERTIES OF SULFATED POLYSACCHARIDES FROM THE ALGA GRACILARIA CAUDATA

KEY WORDS:

Sulfated polysaccharide; oxidative stress; 3T3-L1 cells; anti-obesity; sulfated galactan

PAGES: 51
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

This study aimed to comprehensively evaluate the antioxidant and anti-adipogenic properties of sulfated polysaccharide isolated from the red alga Gracilaria caudata. In an initial screening phase, sulfated polysaccharide-rich extracts (SPREs) were obtained from fifteen tropical macroalgal species and comparatively analyzed regarding their chemical composition and overall antioxidant capacity. Among the investigated species, G. caudata exhibited the highest total antioxidant potential, which guided its selection for subsequent fractionation and detailed structural characterization. Sequential precipitation with acetone of the crude extract from this species yielded three distinct polysaccharide fractions (F1.5, F2.0, and F3.0). These fractions differed markedly in sulfate content, monosaccharide composition, and molecular weight distribution, indicating structural heterogeneity that may underlie their distinct biological activities. In vitro antioxidant assays demonstrated that fraction F1.5 displayed the highest total antioxidant capacity and strong iron-chelating activity, whereas fraction F2.0 was more effective in scavenging hydroxyl radicals. Cytotoxicity evaluation revealed that, among the tested fractions, only F1.5 showed no cytotoxic effects in non-tumor cell lines, supporting its preliminary safety profile. In experiments conducted with 3T3-L1 preadipocytes, F1.5 significantly attenuated H₂O₂-induced oxidative stress by reducing intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Concurrently, it restored reduced glutathione (GSH) content and superoxide dismutase (SOD) activity, achieving effects comparable to those observed with quercetin, used as a reference antioxidant compound. Furthermore, F1.5 inhibited adipogenic differentiation in a dose-dependent manner, as evidenced by decreased lipid accumulation measured by Oil Red O staining and reduced glycerol release into the culture medium. Collectively, these findings indicate that fraction F1.5 exerts dual antioxidant and anti-adipogenic effects, highlighting G. caudata as a promising natural source of bioactive sulfated polysaccharides for potential nutraceutical and functional applications. Nevertheless, further investigations are required to elucidate the molecular mechanisms underlying these activities, confirm efficacy in in vivo models, and assess bioavailability, pharmacokinetics, and long-term safety before considering potential clinical or therapeutic applications.

COMMITTEE MEMBERS:
Externo à Instituição - EDVALDO DA SILVA TRINDADE - UFPR
Externa ao Programa - 2524706 - GIULIANNA PAIVA VIANA DE ANDRADE SOUZA - nullPresidente - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Externo à Instituição - LEANDRO SILVA COSTA - IFRN
Externo ao Programa - 2962496 - RAFAEL BARROS GOMES DA CAMARA - null